I don't need or want someone who just agrees with me on everything, but being contentious and argumentative is just a huge turn off. It's a trend I noticed with American women more than other nationalities.
A lot of guys, myself included, fall into a trap of trying to discuss things logically, finding a solution, and in general reacting to what a woman is saying. It may sound sexist but you kind of can't take what a woman says seriously. Just don't take anything personal. It's vastly improved my relationships with women after realizing this.
You have to of course be careful about the kind of women you invite into your life too. That's why the "ick" is kind of important too. At the risk of being closed minded, I've been much more vigilant of red flags, icks, etc.